Greetings.

I would first like to say, thanks for an excellent site!

I was wondering if anyone could help me out with alignment. I was reading the schematic on the Zenith 10s669 and the alignment procedure is a little confusing. The first step says to connect test osc to the converter grid(Aka the 6A8 tube’s grid pin 4?), put in a dummy antenna of .5Mfd.(Where do I put the capacitor?) set the freq on the generator at 455Kc and adjust the IF trimmers. The second step says that I should connect the signal generator to the Ant-Gnd. with 10ohm shunt(What does that mean? Do I put a 10 ohm resistor across the ant and gnd screw terminals on the back of the chassis? What do I do with wavemagnet? Unplug it?) The dummy ant in step 2 is 400ohms (Where do I put that resistor?) Step 3 – 6 is basically the same this as step 2 other than the different frequencies and the different trimmers to adjust. Step 7 through 10 says that I should connect signal generator to a “single turn loop loosely coupled to wavemagnet”(Do I loop a piece of wire? Where exactly do I connect it to the wavemagnet?) It also seems that there is no dummy antenna on these steps.

I hope I did not confuse anyone. Please feel free to comment. I am new to the alignment of a radio. I usually don’t align, but this radio once rebuilt really wasn’t performing like a 10 tube zenith should. I by ear adjusted all the trimmers and got a lot more volume and stations. The oscillators are off a bit now due to the dial needle and numbers on both far ends of the dial being off frequency.

Thanks in advance!!
Jay

Connect the shielded center lead of your generator lead to the grid terminal of the 6A8. This is the terminal on top of the tube. Use a .5 MFD condenser in series with this lead. The shield lead (outer lead) should connect to the receiver's chassis.

When you shunt the resistor, yes, it should go across the terminals. The shielded outer lead of your generator should go to the GND terminal. The center lead should go to the ANT. The loop antenna should be left plugged in.

For loosely coupling the generator with a single turn of wire, make a loop as per the instructions (hopefully they give you some dimentions, though it isn't too critical). Connect this loop to your generator leads. Place it near the loop antenna.

If you are not using shielded wire on your generator, you should be. You can use any shielded wire found at Radio Shack--say, with RCA plugs on the ends. Cut off any plugs that you don't need. If your generator has one of those RF twist-lock bayonet connectors, these can be purchased with a female RCA socket on the other side (adapter). In this case don't chop off the RCA plug from your shielded wire. SImply plug it into the adapter and then attach the adapter to your generator. Put allegator clips on the other side of the cord. If your generator doesn't have a socket with a center terminal, and you don't know where the shielded (center) lead should connect, you'll have to open up your generator and see which terminal is not connected to the chassis or is connected to through a condenser to the plate of the output tube. This should be for the center wire of your shielded cable.

Thomas

:Greetings.
:
:I would first like to say, thanks for an excellent site!
:
:I was wondering if anyone could help me out with alignment. I was reading the schematic on the Zenith 10s669 and the alignment procedure is a little confusing. The first step says to connect test osc to the converter grid(Aka the 6A8 tube’s grid pin 4?), put in a dummy antenna of .5Mfd.(Where do I put the capacitor?) set the freq on the generator at 455Kc and adjust the IF trimmers. The second step says that I should connect the signal generator to the Ant-Gnd. with 10ohm shunt(What does that mean? Do I put a 10 ohm resistor across the ant and gnd screw terminals on the back of the chassis? What do I do with wavemagnet? Unplug it?) The dummy ant in step 2 is 400ohms (Where do I put that resistor?) Step 3 – 6 is basically the same this as step 2 other than the different frequencies and the different trimmers to adjust. Step 7 through 10 says that I should connect signal generator to a “single turn loop loosely coupled to wavemagnet”(Do I loop a piece of wire? Where exactly do I connect it to the wavemagnet?) It also seems that there is no dummy antenna on these steps.
:
:I hope I did not confuse anyone. Please feel free to comment. I am new to the alignment of a radio. I usually don’t align, but this radio once rebuilt really wasn’t performing like a 10 tube zenith should. I by ear adjusted all the trimmers and got a lot more volume and stations. The oscillators are off a bit now due to the dial needle and numbers on both far ends of the dial being off frequency.
:
:Thanks in advance!!
:Jay

Thank you for the quick reply.

My next question is on step 2, it says that the dummy ant should be 400ohms. Should I put a 400 ohm resistor in series with the center lead of the generator?

Thanks for all the comments. I have a superior instruments model TV-50 genometer. I am still trying to learn how to use it. I do have a manual, but I do question the output it gives. Is there any other way of testing this device without an O-scope?

Usually that is what you do (connect a 400 ohm resistor in series). I assume that this is what they mean in this circumstance. Resistors limit high frequencies, and condensers limit low frequencies (all depending upon the values chosen and the frequencies encountered), so placing a resistor or a condenser in series with the center lead may help reduce harmonic frequencies that might otherwise be accidently tuned in. This is my reasoning. Perhaps someone has a better explanation.

Thomas

Jay
This is not a good choice for your first alignment. You will need a frequency counter to check your signal generator. Your pointer will have to be mechanically aligned with the marks on the dial before you begin. You will have to be familiar with the alignment procedure and your equipment before you start. There are some good sites that explain the operation of your signal generator and how to do alignments. It is a lot easier once you learn what the adjustments are for and how they interact with the other adjustments. I would put this one on the shelf until you have done a few dozen AC/DC radios and are ready for this one.

Dave